tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
leds: lm3601x: Calculate max_brightness and brightness properly
The torch_current_max should be checked not exceeding the upper bound.
If it does, throw a warning message and set to LM3601X_MAX_TORCH_I_UA.
LM3601x torch brigthness register (LM3601X_LED_TORCH_REG) takes 0 as the
minimum output (2.4 mA). However, 0 of led_brightness means LED_OFF.
Adding a -1 offset to brightness before writing to brightness
register, so when users write minimum brightness (1), it sets lm3601x
output the minimum.
Signed-off-by: Jack Chen <zenghuchen@google.com>
Link: https://lore.kernel.org/r/20240704191500.766846-1-zenghuchen@google.com
Signed-off-by: Lee Jones <lee@kernel.org>
+12
-3
+12
-3
drivers/leds/flash/leds-lm3601x.c
+12
-3
drivers/leds/flash/leds-lm3601x.c
···
190
190
goto out;
191
191
}
192
192
193
-
ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness);
193
+
ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness - 1);
194
194
if (ret < 0)
195
195
goto out;
196
196
···
341
341
342
342
led_cdev = &led->fled_cdev.led_cdev;
343
343
led_cdev->brightness_set_blocking = lm3601x_brightness_set;
344
-
led_cdev->max_brightness = DIV_ROUND_UP(led->torch_current_max,
345
-
LM3601X_TORCH_REG_DIV);
344
+
led_cdev->max_brightness =
345
+
DIV_ROUND_UP(led->torch_current_max - LM3601X_MIN_TORCH_I_UA + 1,
346
+
LM3601X_TORCH_REG_DIV);
346
347
led_cdev->flags |= LED_DEV_CAP_FLASH;
347
348
348
349
init_data.fwnode = fwnode;
···
385
384
dev_warn(&led->client->dev,
386
385
"led-max-microamp DT property missing\n");
387
386
goto out_err;
387
+
}
388
+
389
+
if (led->torch_current_max > LM3601X_MAX_TORCH_I_UA) {
390
+
dev_warn(&led->client->dev,
391
+
"Max torch current set too high (%d vs %d)\n",
392
+
led->torch_current_max,
393
+
LM3601X_MAX_TORCH_I_UA);
394
+
led->torch_current_max = LM3601X_MAX_TORCH_I_UA;
388
395
}
389
396
390
397
ret = fwnode_property_read_u32(child, "flash-max-microamp",